I12 RATHBUN 
nearly as far as, or farther than, the spine. 
Hands a little over twice as long as wide 
nigricauda. 
H’. Antero-internal angle of scale is not produced, and 
the spine reaches much beyond the blade. 
Hands two and a half to three times as long as 
wide. 
J. Scale shorter than the Stee exclusive of ros- 
trum =. . : = 4 .« Qlaskenses. 
J’. ‘scale -as long as the carapace, exclusive of 
rostrum . . . . . alaskensis elongata. 
E’. Sixth segment of abdomen convex, not sulcate, beneath. 
FE. Hands very stout, only two and a fourth times as long 
as wide; antepenult segment of outer maxillipeds 
greatly dilated . 2 = Walla. 
F’, Hands elongate, about three and a half times as long as 
wide; antepenult segment of outer maxillipeds not 
ditited as My pee ke coe Me nag aa Teer 
C’. Carapace with 2 median spines. 
D. Both median spines in front of the middle of the carapace. 
E. Rostrum slightly seat has rounded at the tip. Surface 
pubescent’ <°'": . . communis. 
FE’. Rostrum ascending at an angle of 48 degrees, tip pointed. 
Surface naked. 
B., Eyes otsmoderatesizes sy jena) jouw simone) Meme caters 
Fi, Eyes very largess once es aie enue Oy SSOP, 
D’. Posterior of the median spines situated at about the middle 
of the carapace ". 7 21. » gio” 6) at, SSPIUCAIRCQED. 
Bl. Carapace without a median gastric spine aie ae SH Lerostres. 
A’. Gastric region depressed below the general level of the carapace. 
B. Second lateral carina of the carapace (counting from the middle) 
unarmed. 
C. Rostrum not spiniform, extremity obtuse. 
D. First to fourth abdominal segments, inclusive, smooth. 
E. Anterior median spine not advanced so far as the line of 
the: orbitsi <<. 4s ; . 2.) «6Mmuntiia. 
E’. Anterior median spine projecting in front of the line of the 
orbits. ait hoop Uo ehe ie aciet. eu RNCGLELLG Tse 
D’. First to fourth abdominal segments more or less carinated. 
E. First to third segments of the pleon armed laterally with 
2 spines each: <2) sivas 6 os ue Some te SSP UPOSESSeaa. 
E’. First to third segments of pleon unarmed . . variadilts. 
C’. Rostrum spiniform, sharp . . .. .. . © Sfimirostris. 
B’. Second lateral carina of the carapace armed with a spine a little 
behind the superior lateral spine . . . . . « « munitella. 
CRANGON NIGRICAUDA Stimpson. 
Crangon nigricauda STIMPSON, Proc. Calif. Acad. Sci., I, 97, 1856; Jour. 
Boston Soc, Nat. Hist., VI, 496, pl. XXII, fig. 6, 1857. 
